This 86-word list comes from Scrabble Players, which has competitive clubs throughout the United States.

— Bruce D., Scrabble Players Club Number 44, Los Angeles

Cecil replies:

Scrabble knowledge having progressed at a dizzy pace, the number of two-letter Scrabble words recognized in the U.S. has now risen to 96 — here’s a list with definitions, courtesy of San Jose Scrabble Club No. 21. Ought to be enough for anyone, but if it’s not you’re welcome to adopt the anything-goes approach favored in the UK, where it’s said they recognize 101.